C-7 fan hub bearing

Passin Thru wrote:
I'd buy one and wait til it goes out. Not that bad to change but then, I'm a airplane mech and don't mind getting dirty.

Well Sir, buying one ahead of time and keeping it around for that potential time the original one goes out is a good thing. But, not sure if you've EVER looked into ALL the issues of replacing that one bearing. While you may be an air plane tech, getting to that particular bearing is one serious pain in the a$$. And, no one in their right mind, that knows what's involved, would want to even think about doing it in the middle of nowhere.

And, if you've never actually looked at where and how that bearing is kept on the C-7s, I'd do some research. While we speak, I have a buddy that's just gone through some really pains taking ordeal, just to gain access to that bearing. And I'm only speaking of the fan bearing hub retainer. Getting all that's in the way, OUT OF THE WAY, like the radiator, CAC, and more, is a chore in itself.

Then, that fan bearing hub is retained with four, very small, flat head, 4mm Allen Drive screws. Those screws are some of the toughest screws to break loose on that entire engine. 4MM Allen wrenches are not very strong. And those screws, don't want to give up their purchase on that hub, especially since they've been in there for thousands and thousands of miles, heated, then cooled down, then heated and cooled down, hundreds of times. Talk about just a bit of frustration.

My buddies not the only one who's almost dynamited them out of there. And all these so called "Solution" penetrating oils/formulas etc., DIDN'T EVEN TOUCH THESE little screws.

There's been one gent who got smart and, lucky and, welded a nut to each one of the heads, A FEW TIMES before they finally broke loose. But, not many folks carry a welder around in their motor home, while traveling. So, good luck when it comes time to replace it. It's not a fun project.
Scott

To the gentleman who said "I will wait until mine goes out" Well if it goes out, you could be anywhere on the road and pray tell it doesn't send the fan blade into the radiator. The shop rate is based on 15 hours of hard work. Good Luck

pretty fair amount of weight with the fan hangin off the end of the shaft.
To me the best is a grease able one that's kept greased.

I will repeat my earlier post:
"So far, no one has really done an investigation as to why it failed. I can guess of at least 3 reasons why it would. Not pressed in correctly, out of balance fan blade, or anything that would cause the belt to vibrate due to out of balance condition."
It is easy to say the bearing fail.

I'd buy one and wait til it goes out. Not that bad to change but then, I'm a airplane mech and don't mind getting dirty.

Since you guys have been discussing the fan bearing and I am getting ready to go on some long trips, I decided to give it a couple of squirts of grease yesterday. So I crawled under on the passenger side, disconnected the big four inch hose for the CAC from one end. It was easy to get to the fitting. But you do need a grease gun with a three foot long flex hose to get to it and make the job easy. Then just reconnect the big hose and you are done. Takes about 15 minutes.

In case some do not know, there is nothing inside that big hose but air that flows through it, no liquid in there.

427435 wrote:
There may well be a difference in failure rate between an engine that is used often/daily and one that sits for months at a time. Perhaps, when a MH sits for months, the seals in that particular bearing dry-up and the bearing goes bad.

That's probably a pretty good supposition.

There may well be a difference in failure rate between an engine that is used often/daily and one that sits for months at a time. Perhaps, when a MH sits for months, the seals in that particular bearing dry-up and the bearing goes bad.

FIRE UP wrote:

barmcd wrote:

FIRE UP wrote:

tinkerer wrote:
After reading the post about the bearing failure on the C-7 fan hub, I was just going to take a poll who has had a similar problem or is this a more isolated problem. I know forums bring out people who have problems but would like to hear if there are more who haven't has that problem. I happen to be running a C-7 that was built in 2006 and is approaching the 50,000 mile mark and was wondering if I should be more proactive at getting it changed while I am not traveling. By the way mine does not have a grease zerk.:@

tinkerer,
This is NOT a known issue. As you have stated, we read on these forums, of primarily ones who've had to replace that bearing. What about the hundreds or, thousands of the motor homes with the C-7 that are running all over this country and NOT having any issues with that bearing. Not to mention that, the C-7 was installed in many, many kinds of trucks our there. Fire trucks, cement trucks, over the road trucks, local delivery trucks and more. So, while it is smart to be aware of the potential of failure of it, no one really knows or, can predict a failure, at any particular mileage.

It can go at 20K, 30K, 80K or, anytime in between. We presently have 62K on our '04 Itasca Horizon 36GD with the C-7 330HP. Yep, it might be time to me to think about it but, it may go to 80K or more, no one knows. And, as Brett indicates, you can order up the older style ones that were fitted tot the C-7s predecessor, the 3126 version CAT. Then, just make sure you do lube it, every now and then. Good luck.
Scott

I tend to disagree with you. When we were researching for our coach purchase, it became apparent to usthat this was an issue with early 2000 C7s, enough so that we looked to coaches that didn't have the Cat engine. There are lots of threads on all RV forums about the fan.

barmcd,
Nothing wrong with disagreeing, that's why we live in America. I would like to make sure we're on the same page though. Your referring to the "early 2000 C7s". Are you saying "early" as in the year 2000? Or, are you meaning production date of Sept '03 as "early". Because, in the year 2000, the CAT was the 3126 with the lubable fan hub bearing. And that engine continued to mid '03 when the C7s were born to take the 3126 place. This is just so we're talking apples for apples here.

Second, as I and many on here have stated in many past posts and threads, we only read ON HERE and some other RV forums about certain issues. When we first purchased our coach, an '04 Itasca Horizon 36GD with the 330HP CAT C7, I'd heard just a tiny bit of the potential fan hub failure. Well, we had many CATs in our lineup of fire trucks including many with the C7. I spoke with our service MGR and consulted him about my concern.

He was really up on CATs and had done tons and tons of research, talks with CAT techs, other large Fire Departments that were running CATs, Cement truck companies that were running CATS, and, even one large multi-truck over-the-road company that was running CATS. And of all of those people/service managers/techs/FD personnel/long haul drivers/ etc., the amount of failures of that particular bearing was incredibly miniscule in comparison to how many of those engines that not only were running down the road at that time but, were produced in general. And, that engine was also produced for Marine service too. Some of those Marine service engines acquired hundreds and hundreds of hours, failure free.

So, yes, you will read of some on here. And, as usual, any issue on here get's seriously blown out of proportion. All of a sudden, ALL CAT C7s are fan hub bearing failure prone. Well, I guess if folks want to believe that, it's surely up to them.
Scott

Scott, it is a known issue in that many RV owners have experienced the problem. That doesn't mean its an epidemic, or even likely to happen. It's like the broken manifolds in Cummins ISC engines. It's been know to happen and something to consider when buying.

I don't disagree that the great majority of Cat engines won't have a fan fail, but it has been known to happen.

All engines have their quirks it seems, Cummins has had plenty of issues also if you look at forums. A lot of new manifolds had to be replaced, the wrist pin problems, then there is the famous 53 blocks. I even know about some V10 Fords that had some expensive repairs. Anything that goes around can give your trouble!:W